1. V. G. Romanov, Some Inverse Problems for Hyperbolic Equations (Nauka, Novosibirsk, 1972) [in Russian].
2. M. M. Lavrent’ev, K. G. Reznitskaya, and V. G. Yakhno, One-Dimensional Inverse Problems in Mathematical Physics (Nauka, Novosibirsk, 1982) [in Russian].
3. V. G. Romanov, Inverse Problems of Mathematical Physics (Nauka, Moscow, 1984; VNU Science, Utrecht, 1987).
4. A. M. Denisov, Introduction to the Theory of Inverse Problems (Mosk. Gos. Univ., Moscow, 1994) [in Russian].
5. A. I. Prilepko, D. S. Orlovski, and I. A. Vasin, Methods for Solving Inverse Problems in Mathematical Physics (Marcel Dekker, New York, 1999).